Mountain grasslands

The Floraof theSneeuberg

Fulfilling Carl Thunberg'sdesi re to visit the'Sneeuwbergen'

by Ralph Clark and Nigel Barker, Department of Botany, Rhodes

University, Grahamstown

The Great Escarpment in South Africa is known for its plantdiversity and endemism. A spectacular example of this is theKwaZulu-Natal Drakensberg. In fact, South African mountainranges in general appear to be nodes of endemism from theMagaliesberg, with its few endemics, to the 'mega-endemism'of the mountains in the south-western Cape.

Carl Thunberg, dubbed the 'Father of South African bota­ny', travelled extensively in the Cape in the 1700s. However,he never achieved his desire to visit the 'Sneeuwbergen' as hishorses died and the 'field assistants' deserted. Situated in thevicinity of Graaff-Reinet, the Sneeuberg forms an interestingcomponent of the Great Escarpment. Together with its ancil­lary ranges, the Onder-Sneeuberge, the Koueveldberge, theTandjiesberg, the Bankberg and the Renosterberg, it formsa continuous, dolerite-dominated massif stretching 200 krn

from Murraysburg in the west to Cradock in the east. Most ofthe range exceeds 1 800 m in altitude, and much of it exceeds2 000 m. The range includes the relatively well-known'Matterhorn of the Karoo', the Compassberg, which is thehighest peak in the Great Karoo at 2 503 m above sea level,and the lesser-known Nardousberg, which at 2 429 m is thesecond highest peak in the Great Karoo. Not inappropriatelynamed, snow can fallon the range in nine months of the year,and 'white-outs' have been known to occur even in January.

Situated in an otherwise arid area (precipitation for the sur­rounding plains is less than 400 mm per annum, decreasingfrom east to west), the Sneeuberg receives precipitation in theform of convection storms, snow and mist that is unavailableto the surrounding plains. This, together with the moderat­ing effect of altitude, has resulted in a relatively cool mon­tane grassland vegetation markedly different from the loweraltitude, surrounding Nama Karoo. Cool, moist mountains inarid areas are known to be rich in endemics.

The Sneeuberg is physically disjunct from other sectionsof the Great Escarpment, and is climatically distinct from

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ABOVE: The red Itata lily, Cyrtanthus macowanii on the Sneeuberg, in the AsanteSana Private Game Reserve. The species occurs from the Ouberg north otGraaff-Reinet to the Boschberg behind Somerset East, and flowers in July andAugust. Photo: R. Clark.

the surrounding plains. As most of the range is botanicallyunder-collected, and occurs in a region of several converg­ing veld types (including fynbos, grassland, Nama Karoo andthicket), it has been necessary to have a closer look at theflora of the Sneeuberg.

Several endemics are known to occur on the range, and itsgeographic position suggests a link between the floras of theCape Fold Mountains and the KwaZulu-Natal Drakensberg.Although situated near the arbitrarily defined Albany Centreof Endemism that dominates the Eastern Cape, the absenceof thicket vegetation on the range suggests that the Sneeubergis not part of that centre, but part of the Great Escarpmentsuite of centres: the Soutpansberg Centre, the WolkbergCentre and the Eastern Mountain Region (the Kwazulu­Natal Drakensberg and Lesotho). An investigation into highlyrestricted endemic species may provide important clues to thebiogeographic history of a region, and research on the floraof the Sneeuberg is being undertaken as an M.Sc. throughRhodes University. We hope to compile a flora for the rangeand to compare it to the flora of other ranges in the Easternand Western Cape (the Katberg-Winterberg-Arnatole complex,the Stormberg, the Nuweveldberge, the Cockscomb-GrootWinterhoekberge and the Zuurberg) to ascertain whether the

Sneeuberg is a centre of endemism onthe Great Escarpment. As floristic sur­veys are considered to be of benefit to

conservation, the research project mayalso be helpful for local conservationinitiatives.

Sneeuberg vegetationThe vegetation of the Sneeuberg

includes several vegetation types.

The lower slopes are dominated byshrubby Nama Karoo elements suchas renosterbos Elytropappus rhinocero­tis, Euryops annae, Rhus dregeana,Dodonaea thunbergiana, Melolobiumspecies and Lessertia jrutescens Jfor­merly Sutherlandia jrutescens), whilstthe south-facing kloofs and ravines

are characterized by dense bushveldand incipient forest dominated by treesand shrubs like dogwood Rhamnusprinoides, cheesewood Pittosporum

viridiflorum, glossy current Rhus lucidaforma lucida, the common spike-thornGymnosporia buxifolia, wild olive Oleaeuropaea subsp. africana, white stink­

wood Celtis africana and sweet thornAcacia karroo. The Nama Karoo and

bushveld elements give way to denseMerxmuellera-dominated grassland atapproximately 1 700 m above sea level,while ouhout Leucosidea sericea - sage­wood Buddleja salviijolia communities

dominate the high altitude drainagelines and scree slopes. High altitude

Drakensberg elements on the rangeinclude Guthriea capensis, a spinach­like plant that grows in rock crev­

ices and cliffs above 2 000 m andwhich reaches its western limit in theSneeuberg. 'Alpine meadows' of yel­low buttercup Ranunculus multifidusand blue forget-me-not Myosotis occur

along the bases of the moist, cool,south-facing cliffs, as do a variety ofsoft grasses and other herbaceous spe­cies incongruent with the generallyharsh Karoo environment. Fynbos ele­ments are evident in the form of almost

pure stands of the restio Ischyrolepisdistracta below the Nardousberg sum­mit. Two families endemic to the CapeFloristic Region, Grubbiaceae (one spe­

cies on the Sneeuberg) and Penaeaceae(two species on the Sneeuberg), occur

on the range. Additional fynbos ele­ments include at least five Erica speciesand three or four Cliffortia species.

A centre of endemism?My initial look at the Sneeuberg's

vegetation suggests that it may well

be a centre of endemism. Togetherwith the Amatole-Katberg complex and

the Stormberg, it has been describedas a general centre of diversity forthe daisy family (Asteraceae) and sev­eral other genera also have species

endemic to the range, including Selago,Lessertia, Erica, Kniphofia and Cliffortia.Interestingly, the range also has sev­eral faunal endemics that include the

Compassberg skolly butterfly Thestorcompassbergae that is endemic to theCompassberg, and the plain mountainadder Bitis inomata that is endemic tothe Sneeuberg.

So it would appear that the Sneeuberghas weak evolutionary links to the Cape

Floristic Region from the south andwest, with Drakensberg elements fromthe east dominating the flora. This ispossibly because of an 'altitude bridge'linking the Sneeuberg to the Stormberg­Drakensberg system north of the FishRiver basin.

Some interesting research resultsto date include a possible new spe-

ABOVE: An 'alpine meadow' of buttercups (Ranunculus multifidus) and forget-me-nots (Myosotis) below south-facing cliffs on the Sneeuberg, some 2 000 m abovesea level in the Asante Sana Private Game Reserve. Cool, shady south-facing cliffs host many soft plants that are out of place in the otherwise harsh Karoo environ­ment. Photo: R. Clark.BELOW LEFT: The igneous nature of the Sneeuberg can be seen in this easterly view from the Nardousberg summit. At 2 249 m above sea level, the Nardousberg isthe second highest peak in the Sneeuberg. Photo: R. Clark.BELOW RIGHT: An Ischyro/epis distracta community below the Nardousberg summit. This is a common restio on the Sneeuberg. Photo: R. Clark.

"Cool, moistmountains in aridareas are knownto be rich inendem ics."

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LEFT: The Tandjiesberg summit near GrootSuurkop, Asante Sana Private Game Reserve. Thealtitude here is just below 2 000 mabove sealevel. The boulder piles were 'haunted' by severalDrakensberg rockjumpers! Photo: R. Clark.

BELOW LEFT: Brunsvigia radulosa occurs occa­sionally on the Sneeuberg, flowering in summer.Photo: R. Clark.

BELOW CENTRE: Kniphofia stricta on theCompassberg. With Kniphofia triangularis subsp.triangularis, it is common in the Sneeuberg.Photo R. Clark.

BELOW RIGHT: Brunsvigia grandiflora alongSwaershoek Pass in the Bankberg. Photo: P. Weston.

BOTTOM: At 2 504 m above sea level, theCompassberg is the highest peak in the GreatKaroo. Its distinctive shape has lead to it beingcalled the 'Matterhorn of the Karoo'. Photo R. Clark.

RIGHT: Guthriea capensis (Achariaceae family) reaches its western limits in the Sneeuberg. The plant is ahigh altitude species that confirms the Sneeuberg's links with the Drakensberg. Photo: P. Weston.

BELOW: Map showing the altitudinal links and disjunctions along the Great Escarpment, south-east SouthAfrica. (Thanks to Ms G. McGregor, Department of Geography, Rhodes University.)

ABOVE LEFT: The Great Escarpment of the Sneeuberg, looking east from Waterkloof in the Asante Sana PrivateGame Reserve. Exceptional rains in the second half of summer 2005/2006 rendered the landscape almost asgreen as the Kwalulu-Natal Drakensberg. Photo: P. Weston.ABOVE CENTRE: The Great Karoo from the summit of the Compassberg. Photo: R. Clark.ABOVE RIGHT: The ink plant Harveya cf. pumila on the Compassberg. Photo: R. Clark.RIGHT: Kniphofia acraea is restricted to the Bankberg near the Mountain Zebra National Park. This is only thethird time it has been recorded. Photo: P. Weston.

What does that mean?

ancillary Subordinate.disjunct This describes plant species, usuallyendemic, that are found in two or more widelyseparated regions but nowhere in between. Thisimplies that they represent the relicts of oncewidespread species.The Great Escarpment The central plateau orhigh lying land that forms most of the interior ofSouth Africa.montane Occurring in mountainous country.endemic A species occurring in one particulararea only and nowhere else.biogeography The study of geographical aspectsof the distribution of plant and animal life.incipient forest The early stages of forestgrowth.

and Cape buffalo. Photographic oppor­tunities of the phenomenal mountainand floral scenery abound, and thereare great opportunities for climbing.The three highest points in the range,the Compassberg, Nardousberg and anunnamed peak in the Renosterberg,have all been happily climbed, notto mention a side-trip up Cockscombwhich resulted in some vertigo-stressand more ericas than I know what to dowith. Overall, I am sure the project willcontribute to further botanical knowl­edge of our amazing Eastern Capeflora.@

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AcknowledgementsThe financial assistance of the National Research Foundation (NRF) towards this researchis acknowledged. Opinions expressed are those of the authors and are not necessarily to beattributed to the NRF. Grateful thanks are made to the various landowners for access and per­mission to collect, as well as to the Selmar Schonland Herbarium and the various specialistsand taxonomists who have assisted in plant identification.

des of Hennannia, and the third-everencountered population of the red-hotpoker Kniphofia acraea. Since October2005 some 1 400 plant specimens havebeen collected with at least one sig­nificant range extension (Zaluzianskyapulvinata, from the Stormberg to theCompassberg) .

The project is also proving enjoyablein terms of the abundant wildlife thatincludes cheetah and kori bustard, andDrakensberg rockjumpers on the sum­mit plateaus. Private landowners havere-introduced several of the Big Five,including white rhino, African elephant

December 2006 Veld&Flora 205